The present invention relates to a fuel injection control method for an engine and more particularly to an asynchronous fuel injection method suitable for determining the amount of asynchronous fuel injection (or an asynchronous injection) required for transient fuel compensation during rapid acceleration of the engine.
The conventional asynchronous fuel injection method injects an amount of fuel meeting the variation of the quantity of air when the throttle valve is suddenly opened so that a predetermined quantity of fuel corresponding to the variation of the throttle angle is injected. To be sure, this attempts to compensate for the variation of air quantity which, due to a delay in the detection of air quantity by an air quantity sensor, is unable to follow the fixation of the air-fuel ratio at rapid acceleration of the engine through the variation of the throttle angle as predicting information. However, the variation of air quantity at rapid engine acceleration is considered to be affected not only by the varying throttle angle but also by the intake manifold pressure, atmospheric pressure and sucked air temperature whereas the conventional method has not been controlled in consideration of these factors.